Investigation of sensing behavior of carbon nitride (C₆N₈) for detection of phosphine (PH₃) and phosphorous trichloride (PCl₃): A DFT approach

This study shows the exploration of the gas‐sensing capabilities of C 6 N 8 material against toxic gases like phosphine (PH 3 ) and phosphorous trichloride (PCl 3 ). First‐principles study based on M05‐2X/LanL2DZ (d, p) method was performed to investigate the interaction energy ( E int. ), frontier molecular orbitals (FMOs), natural bonding orbital (NBO), noncovalent interactions (NCIs), partial density of states (PDOS), molecular electrostatic potential (MEP), and quantum theory of atoms in molecules (QTAIM) analyses. The interaction energy results showed that PCl 3 @C 6 N 8 (−23.45 kJ/mol) is more stable than PH 3 @C 6 N 8 (−14.79 kJ/mol). A considerable decrease in the HOMO‐LUMO band gap of C 6 N 8 was observed as a result of its complexation with the analytes. QTAIM and NCI analyses indicated the presence of weak noncovalent interactions between C 6 N 8 and gases (PH 3 and PCl 3 ). SAPT0 analysis was performed to quantify the NCIs. MEP maps of complexes revealed the localization of electronic density on C 6 N 8 . The little recovery time of complexes (determined at 300 K) showed that C 6 N 8 can serve as a reusable sensing material against PH 3 and PCl 3 . Our results demonstrate that the C 6 N 8 surface is a reliable material for detecting phosphine and phosphorous trichloride gases.